Syrian opposition representatives have taken Syria's seat at an Arab League summit held in Qatar in a significant diplomatic boost for the forces fighting President Bashar Assad's regime.

A four-man delegation led by Mouaz al-Khatib, former president of the Syrian National Coalition, took the seats assigned for Syria today at the invitation of the Emir of Qatar, Sheikh Hamad bin Khalifa Al Thani.

The decision for the opposition to take Syria's seat was made at the recommendation of Arab foreign ministers earlier this week in the Qatari capital, Doha.

Syria's membership in the Arab League was suspended in 2011 in punishment for its crackdown on the opposition.

As well as Mr al-Khatib, the Syrian delegation included Ghassan Hitto, recently elected prime minister of a planned interim government to administer rebel-held areas in Syria, and two prominent opposition figures, George Sabra and Suheir Atassi.

Addressing the gathering, Mr al-Khatib thanked the Arab League for granting the seat to the opposition.

"It is part of the restoration of legitimacy that the people of Syria have long been robbed of," he said.

The diplomatic triumph won by the opposition, however, could hardly conceal the disarray within its top ranks.

Mr al-Khatib announced his resignation this week out of frustration with the amount of international support for the opposition and problems inside the body itself, but the coalition rejected it. He has said he will discuss the issue later.

Also, Mr Hitto's election as the head of the interim government was rejected by the opposition's military office, which said he was not a consensus figure. Some members have accused Qatar and the Muslim Brotherhood of imposing their will on the council.

In Damascus, the government blasted the Arab League's move to allow the opposition to take its seat at the Doha summit, portraying it a selling-out of Arab identity to please Israel and the United States.

"The Arab League has blown up all its charters and pledges to preserve common Arab security, and the shameful decisions it has taken against the Syrian people since the beginning of the crisis and until now have sustained our conviction that it has exchanged its Arab identity with a Zionist-American one," said an editorial in the Al-Thawra newspaper, a government mouthpiece.

"The Syrians are fully aware that this is not a summit of the Arabs, and Arabism means nothing without Syria," it said, adding that recognising the opposition "legitimises terrorist acts that are committed overtly and blatantly against the Syrians, their institutions and properties".

The Syrian government says the conflict is an international conspiracy to weaken Syria being carried out by terrorists on the ground.

The crisis began in March 2011 with protests demanding the ousting of Mr Assad.

With a harsh government crackdown, the uprising steadily grew more violent until it became a full-fledged civil war. The United Nations estimates that more than 70,000 people have died so far in the conflict.